Telephony



' (no Model.)

J. W. GIBBONEY.

TELEPHONY.-

No. 481,529. Patented Aug. 23, 1892.

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JOHN WV. GIBBONEY, OE LYNN, MASSACHUSETTS.

TELEPHONY.

SPECIFICATION forming part of Letters Patent No. 481,529, dated August23, 1892.

. Application filed February 8, 1892. Serial No.420,626- (No model.)

T or whom it may concern.-

Be it known that 1, JOHN W. GIBBONEY, a citizen of the United States,residing at Lynn, in the county of Essex and Commonwealth ofMassachusetts, have invented a new and useful Improvement in Telephony,of which the following is a specification.

The present invention relates to a method of setting up waves in anelectric circuit in response to vocal sounds or other mechanicalimpulses transmitted to the apparatus which corresponds to the ordinarytransmitters in telephone systems.

It consists, briefly, in putting on the line a set of pulsations oralternations of current from a suitable source, which are made to passthrough the turns of a coil in inductive relation, as in transformers orinduction coils, to another coil or coils, the current in which lattercoil or coils is made to vary by a change in inductive capacity, orchange of resistance, or self-induction, or changes of these effectsjointly to a greater or less extent brought about by the vibrations ofthe voice, as in speech transmission, or other mechanical impulsesimparted to the transmitter or diaphragm provided therefor.

The changes of capacity, self-induction, resistance, or both, or all,which correspond to the changes of sound, act inductively to vary theprimary currents traversing the line, and may therefore affect distantinstruments placed in series therewith or placed in such connection thatthey may respond to the variations. Such an instrument is an ordinarytelephone-receiver.

The invention will be'understood by reference to the accompanyingdrawings. It may be here remarked that the invention is applicable toexisting systems of telephonic communication and dispenses with the useof batteries; but it is not the purpose of the present invention todescribe such a system, but to describe the invention in its broad form,leaving further extensions thereof to subsequent applications.

In Figure 1 is shown a line L, connecting a telephone-receiver, as at R,with apparatus consisting of a receiver R in circuit with a (3011 P andan alternating-current generator or generator of alternating or varyingimpulses, as at A. The earth-plates E E serve to return In inductiverelation core or wound parallel to the coil P, is a secondary coil S,which is combined with an arrangement for receiving the waves of thevoice and increasing or diminishing in ac cordance with the vibrationsof the voice the inductive effect of the coil P in the magnetic circuitof the coil S. If the coil S be of very fine wire, so that the currentsflowing in it are of considerable potential, two plates forming thesurfaces of a condenser or static telephone-transmitter, as at B, may beused, one of them being a diaphragm to receive the vocal waves or to betalked against, and the other being fixed, so that as the diaphragmflexes or moves it approaches more or less closely to the other plateand changes the static capacity of the dielectric layer between. Thechanges result in varying in accordance with the changes of the Waves ofthe voice the induction between the coils S and P, so as to modify theoriginal wave by the superposition of the vocal waves. If, as stated,the original waves are but slightly audible or inaudible waves, thevocal waves retain their characteristic of audibility and may betransmitted to the line and carried to a receiver or receivers R R inthe same circuit or a circuit in inductive relation thereto. Incharacterizing the orignal waves as slightly audible or inaudible I ofcourse desire to convey the idea that they do not seriously affect thetransmission of speech or are not annoying.

There are other ways of accomplishing the result than by the use of thestatic transmitter B. For example, in Fig. 2 the arrangements are thesame as in Fig. 1, with the exception that the secondary coil S 'is ofquite low resistance or consists of but few turns of insulated conductorand has in its circuit an ordinary carbon transmitter T for receivingthe vocal waves; or, in case the secondary cir- ICO . mitters, if needbe.

cuit S is of still lower resistance, the transmitter T may have aconducting-diaphragm forming one pole and a metallic button of goodconductivity resting thereon forming the other pole. In fact, withsufliciently few turns in this coil electrodes of pure silver may beused in the transmitter, or, again, electrodes of silver amalgamatedwith mercury may be used, the variation of resistance in the circuit ofthe coil S being due to the variations of section in the mercury or thevariation in the contact-resistance between the two surfaces, one movedby the diaphragm and the other resting against the first. evident thatany well-known form of transmitter which varies the resistance of thecir-fcuit by the sound of the voice may be inserted into the circuit ofthe coil S'and subserve the purposes of the invention, it only beingnecessary to adapt the number of turns of the coil S to the normalresistance of the transmitter itself. Instead of varying resistance,

of course the movement of an iron core in a coil or the movement of acoil over an iron core accomplished by the voice might be used to varythe selfinduction in the circuit of the coil S, and thus modify thewaves of current induced in it from the primary P, which induced'wavesreact upon the primary P and cause the transmissionof correspondingwaves to the line and to the regzeivers on the line.

It will be understood that my invention permits the use of any potentialin the coil P and the line, and permits, also, the use of current of anydesired potential on the secondary or transmitter circuit, and this isin fact one of the main features of my invention. It also dispenses withbatteries, feeding current through the transmitter, and the generator A,feeding the alternating impulses or other impulses, may of course belocated at any convenient point far away from the trans- Thefield-magnets of the alternating-current or varying-current generator Amay also be excited in any suitable manner-such, for instance, as by aseparate winding upon its armature, as shown'in Fig. 1, in which thefield-magnet M is shown connected to brushes on a commutator fordelivering currents suitable for such purpose or by a battery, asindicated at J, Fig. 2.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is

1. The method of transmitting speech, consisting in passing over theline-waves of alternating current or varying current of slightaudibility in the receivers and superposing thereon waves of currentcorresponding to vocal waves, substantially as described.

2. The method of transmitting speech, consistingin putting upon the linealternating or pulsating waves of current inaudible, or nearly so, inreceivers and inductively superposing waves of current corresponding tothe vocal waves received by a transmitter.

3. The method of transmitting speech, consisting in passing over a lineor circuit, in cluding .the receivers andtransmitting devices, wavesofelectric current incapable or 7 nearly incapable of producing audibletones i in the receivers, and modifying the induction; betweenthelinetransmitter-coil and a local coil in inductive relation theretothrough the agency of voice-waves.

4. The method of transmitting speech along a line havingreceivers andtransmitters,-consisting in producing induction between'a pulsating oralternating current in'the line of such rate as not to producestrongly-audible 8 tones or sounds in the receiver and a local j circuitin inductive relation to a coil in the line and modifying theresistance, capacity, or self-induction of such local circuit by thevocal waves received by the transmitter. 8

5. In combination with a telephone -.line having receivers thereon ofmeans for producing in said line varying or alternating current impulsesof such period as not to produce strongly-audible tones or sounds inreceivers, and means, such as a local coil in inductive relation to acoil in the line, for superimposin g undulations inductively transferredfrom the local coilto the line-coil, the local coil being provided witha telephone-transmitter in 9 its circuit, whereby the capacity or theresistance of its circuit may be varied by the waves of the voicecommunicated to said transmitter. V

6. In atelephone systemin which alternat- I ing or varying impulses arepassed over the line, an induction-coil the primary of which is in theline and the secondary of which is local to the transmitter andconnected to the said transmitter, whereby the variations of 1resistance, capacity, or self-induction set up in the transmitter by thevoice-waves are inductively transferred to the primary coil in -the lineto vary its current or superimpose the vocal undulatory current on thealternat- 1' ing or varying line-current. I i a 7. The combination, in atelephone system, of an induction-coil provided with a primary coil ofmany turns traversed by alternating or varying impulses of current, andalso pro- 1 vided with a secondary coil of few turns 10- callyconnectedthrough a transmitter, whereby the resistance of said localcoil-circuit is varied, as described, and for the purpose specified. I 18. The combination, in a telephone apparatus, of a source of alternatingor varying electric current, a line-circuit connected to said currentsource, atransformer or inductorium the primary coil of which is in saidline-circuit or inductively related thereto, anda sec- 1 ondary circuitfor said transformer, whose resistance, capacity, or self-induction isadapt ed to be modified by sound-waves, as set forth; .1 9. The methodof telephoning, consisting in passing over a circuit an alternatingcurrent or a current periodically changing in value and inductivelymodifying said current in correspondence with sound-vibrations.

10. The method of telephoning, consisting ing the counter-induction ofsaid device by in passing over a circuit an alternating curthe agency ofsound-vibrations, whereby the rent or a. current of changing value,passing said current is made to flow over said line in 15 said currentthrough a coil of an inductoriuln, impulses 0r waves corresponding tothe sound and varying the counter-induction of said vibrations. 1inductorium by the agency of sound-vibra- Signed at Lynn, Massachusetts,February tions. 4, 1892.

11. The method of telephoning, consisting in feeding the line with anelectric current of periodically rising and falling potentia1,-passingsaid current through a counter-inductive device included in theline-circuit, and vary- JOHN W. GIBBONEY.

Witnesses:

ALEX. F. MACDONALD, JOHN T. BRODERICK.

